Abstract
Conventional imaging of diagnostic ultrasound is widely used. Although it makes the differences in the soft tissues echogenicities’ apparent and clear, it fails in describing and estimating the soft tissue mechanical properties. It cannot portray their mechanical properties, such as the elasticity and stiffness. Estimating the mechanical properties increases chances of the identification of lesions or any pathological changes. Physicians are now characterizing the tissue’s mechanical properties as diagnostic metrics. Estimating the tissue’s mechanical properties is achieved by applying a force on the tissue and calculating the resulted shear wave speed. Due to the difficulty of calculating the shear wave speed precisely inside the tissue, it is estimated by analyzing ultrasound images of the tissue at a very high frame rate. In this paper, the shear wave speed is estimated using finite element analysis. A model is constructed to simulate the tissue’s mechanical properties. For a generalized soft tissue model, Agar-gelatine model is used because it has properties similar to that of the soft tissue. A point force is applied at the center of the proposed model. As a result of this force, a deformation is caused. Peak displacements are tracked along the lateral dimension of the model for estimating the shear wave speed of the propagating wave using the Time-To-Peak displacement (TTP) method. Experimental results have shown that the estimated speed of the shear wave is 5.2 m/sec. The speed value is calculated according to shear wave speed equation equals about 5.7 m/sec; this means that our speed estimation system’s accuracy is about 91 %, which is reasonable shear wave speed estimation accuracy with a less computational power compared to other tracking methods.
Highlights
Replacing healthy soft tissues by fibrotic tissues is the pathological change that may cause a malignant or benign tumor
The resulting shear wave is tracked by B-mode ultrasound imaging at a high frame rate and its speed is estimated to calculate the stiffness of the phantom; which is a mechanical property of the phantom; using Matlab software version R2010a
The shear wave speed is estimated as the distance difference between two nodes divided by the time difference at which the Time-To-Peak displacement (TTP) are occurring for these two nodes
Summary
Replacing healthy soft tissues by fibrotic tissues is the pathological change that may cause a malignant or benign tumor. Deformation; is a result of stress over the tissue; formerly, it was manual palpation over the tissue Nowadays, it is the beat or the push that is caused by the acoustic radiation force generated by the ultrasound probe, a procedure called Elastography procedure. This section aims to give the reader a proper background about the mathematical equations involved in the field of elastography, the assumptions made to simplify the calculations and the limitations that are found if the tissue is modeled as viscoelastic and non-linear It is worth speaking about the strain, which is the deformation caused by the stress, and to highlight its behavior in the finite element models and its relationship with displacement induced. Strain (ε) is related to the tissue displacement by (1) [1, 2], and shown in Figure 1. (1)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Advanced Computer Science and Applications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
